# expit
> Compute the [standard logistic][logistic-function] function.
The [standard logistic][logistic-function] function, also called the expit function, inverse logit, or sigmoid function, is defined as the [logistic][logistic-function] function with parameters (`k = 1`, `x0 = 0`, `L = 1`).
## Usage
```javascript
var expit = require( '@stdlib/math/base/special/expit' );
```
#### expit( x )
Computes the [standard logistic][logistic-function] function.
```javascript
var v = expit( 0.0 );
// returns ~0.5
v = expit( 1.0 );
// returns ~0.731
v = expit( -1.0 );
// returns ~0.269
v = expit( Infinity );
// returns 1.0
v = expit( NaN );
// returns NaN
```
## Examples
```javascript
var randu = require( '@stdlib/random/base/randu' );
var expit = require( '@stdlib/math/base/special/expit' );
var x;
var i;
for ( i = 0; i < 100; i++ ) {
x = randu();
console.log( 'expit(%d) = %d', x, expit( x ) );
}
```
[logistic-function]: https://en.wikipedia.org/wiki/Logistic_function
